Purchase online your ticket and go directly to turnstile. Choose the stage and pay with your credit card. You will receive by email your ticket (you can print the ticket or save it in your smartphone), scan it on the orange scanner on the turnstile located at the gates of the lift.
Kids born after 30/11/2013 are free and without ticket. Junior (born after 30/11/2005) and other discounted ticket are available at the ticket office.